docs: def _render_list(self, items, empty='<pre>&lt;empty&gt;</pre>'):
      """Renders an HTML list with the specified list of strings.
  
      Args:
        items: the iterable collection of objects to render.
        empty: what to render if the list is None or empty.
      """
      if not items or len(items) == 0:
        self._segments.append(empty)
        return
      self._segments.append('<ul>')
      for o in items:
        self._segments.append('<li>')
        self._segments.append(str(o))
        self._segments.append('</li>')
      self._segments.append('</ul>')